I am a teacher and my husband works in construction. 

Would it be more expensive to buy an older property like this vs buying a new construction in TX? 

Can you carry the property for the construction period?

If in your shoes I think I'd call sellers bluff and put em against the wall of it via how I construct the purchase offer.

Quote from @Dan Grove: Some combination of cash to seller, closing costs, repairs, construction, paying off arrears, assignment fees, commissions.   

I pitched her even getting a real estate agent license to contribute to the venture as she used to sell new construction when she first started out in sales.Ultimately, you are asking them to put a huge amount of trust in you and go along with making a large financial commitment with you.

This isn't a lending requirement but have some boots on the ground other than just the construction company.

Through your local bank that you are using, are you reapplying for each new home for a seperate construction loan or are you setup as a credit line with them and just submit a new budget for each new home I do want to also add that my banker who is the VP of lending and branch manager has been banking me for 30 years..WE have been through all he ups and downs including the GFC were I got almost totally wiped out financially..

I do see many investors incorporating a similar strategy with new construction builds, heavy rehabs, or in instances where the property was bought far below market value (usually a wholesale type transaction).

I'd like to clarify my assumptions (numbered below), and I would be interested in (constructive) feedback, especially from, the OP.1.